Fail-safe device for porting stored rocket motors



y 1965 E. N. OELAND, JR

FAIL-SAFE DEVICE FOR PORTING STORED ROCKET MOTORS g Sheets-Sheet 1 Filed Dec.

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FAIL-SAFE DEVICE FOR PORTING STORED ROCKET MOTORS Filed Dec. 16, 1963 2 Sheets-Sheet 2 INVENTOR.

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ERNEST N. OELAND,JR.

United States Patent 3,135,636 FAIL-SAFE DEVHJE FOR PURTING STGREE) RUJKET MOTGRS Ernest N. fleland, Jr., West Qovina, Calih, assignor to the United States of America as represented by the Secretary of the Navy Filed Dec. 16, 1%.), $63!- No. 331,4?72 9 Claims. (Cl. 89-437) (Granted under Title 35, US. Code (1.952), sec. 266) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

This invention relates to rocket propelled missiles and more particularly to apparatus for reducing hazards to ships and personnel during storage of such missiles in a ship magazine and during transportation to and loading into a deck launcher.

An example of a missile which may employ the invention is the ASROC missile disclosed in patent application of Orville J. Saholt et al. for Rocket Thrown Missile, Serial No. 8,201, filed February 1 1, 1960. Briefly, this missile comprises an explosive payload at its forward end, a solid propellant rocket motor at its rear end, and an intermediate separable air frame connecting the payload and motor. The motor is provided with a nozzle plate at its rear end having an annular row of angularly spaced nozzles through which the products of combustion may exhaust to provide thrust. The launcher employed with this particular missile is disclosed in US. Patent No. 3,106,132 to Bierman et al.

It is conventional practice to store missile motors or assembled missiles in a ship magazine in compact relationship. When ready for use they are then transported to the launching ship deck and loaded into the launcher with suitable loading equipment such as with the loading crane disclosed in the patent to Eaton No. 2,987,963,

for Boom Missile Loader.

In one mode of handling ASROC missiles, prior to being loaded onto their launching rails in the launcher, the missiles may be stored as components in the magazine of a supply or ammunition tender ship. The magazine may contain a plurality of motors disposed in compact relationship and an assembly compartment in which they are assembled to the air frames and payload. Thereafter, the assembled missiles may be transported from the tender to the launching vessel for direct loading onto the launching rails. In another mode, the assembled missile may be transported to a magazine on the launching ship, which magazine provides means for replenishment of the ship launcher. Regardless of whether or not the motors are in assembled or non-assembled condition, they present a considerable hazard, both to ships and personnel, since the unauthorized ignition of one motor may cause ignition of other motors stored in the vicinity. Unauthorized ignition could occur as a result of overheating of the propellant, enemy fire, vibration, or other causes. To reduce such hazards, it has been the practice to provide each motor with an anti-propulsion device in the form of a removable plate which deflects the propulsion gases to radial directions, this plate remaining on the motor until a missile is loaded into the launcher. While this plate minimizes hazards which would result from random propulsive movement of an ignited motor while within a magazine, or during its transportation, it presents a hazard to other motors stored in its vinicity since the radial gas blast may ignite other motors disposed within the blast. A further precaution against a chain action ignition of all of the motors, while stored in a magazine, is provided in the form of a magazine sprinkler system which will flood the magazine in event of a certain rise of tempera- 3,lh5,36 Patented May 25, 1965 ture and pressure within the magazine. While this might be adequate to cool the magazine in event of burning of a single motor grain, it is considered inadequate to cool the magazine in event of the ignition of a plurality of motors since the burning time of a grain is only four seconds, during which time about 200 pounds of hot gas would be released into the magazine by only a single motor. Explosion of the magazine or severe damage to it or other parts of the ship is thus possible. To obviate such possible damage by provision of more rapid response to heat and pressure within the magazine to activate the sprinkler system and provision of sufiicient coolant with the short response time appears unfeasible in view of the tremendous quantity of heat energy which could be released within only a matter of seconds and with which no practical coolant pumping system could cope.

One of the objects of the invention is to provide transportation and storage safety apparatus for materially increasing the normal burning time of a rocket motor propellant, whereby its rate of heat dissipation is materially reduced.

Another object, consonant with the foregoing object, is to reduce the rocket thrust.

Another object, also consonant with the previous objects, is to employ such apparatus while rocket motors are stored in a ship magazine, so that the rate of heat dissipation, if the motor should become activated, is sufficiently reduced to permit a magazine sprinkler system to cool the magazine and prevent further activation of other motors stored therein.

Another object is to render the rocket motor non-propulsive, or substantially so, as previously in the art, but without the use of a deflector plate to thus effect discharge of gas in an axial direction, rather than in a radial direction toward an adjacent motor.

A further object is to provide substantially fool-proof indicia which will prevent loading a missile into the launcher without its being readied for launching after being so loaded.

Another object is to prevent removal of an unfired missile, such as a defective missile, from the launcher unless its motor has been returned to its non-propulsive and slow burning condition.

Still further objects, advantages and salient features will become more apparent from the description to follow, the appended claims, and the accompanying drawing, in which:

FIG. PA (prior art) is a longitudinal central section through the rear end of a rocket motor,

FIG. 1 is a like section taken on line 1-1, FIG. 3, illustrating modifications to FIG. PA, and forming the subject of the invention,

FIG. 2 is a section like FIG. 1, showing another arrangement of parts,

FIG. 3 is a rear elevation, as viewed in the direction of arrow 3, FIG. 1, and

PEG. 4 is an elevation of a detail as viewed in the direction of arrow 4, FIG. 1.

Referring first to "FIG. PA, a rocket propulsion motor it), employed with the ASROC missile prior to the present invention, comprises a nozzle plate 12, secured in any desired manner to the rear end of motor tube 14, the latter containing an outer solid rocket grain 16 and an inner grain 18, supported by rod 29, for producing gas for exhaust through twelve angularly spaced nozzles 22. To render the motor non-propulsive until loaded into the launcher, a gas deflector plate 24 is provided which threadedly and removably engages the nozzle plate. When disposed on the motor, gas exhausting in parallel axial directions from the nozzles is deflected outwardly in all radial directions, thus neutralizing motor thrust. In addition to this function, the outer edge of the plate provides 3 an abutment 26 against which a rammer 23 may engage to push the missile to its launching position on the launcher rail. A like abutment 3&1, against which a pulling hook 32 may engage, provides means for withdrawing the missile from the rail. In operation, the deflector plate remains on the missile at all times until the missile is rammed into the launcher and secured to same, after which it is removed. To ensure that it is removed, a

projecting finger 34 is provided which will puncture a diaphragm 36, for closing the rear end of the launcher cell, if the diaphragm is applied without removing plate 24 and reveal, upon inspection, that plate 24 had not been removed. In event it is desired to remove an unfired missile, the deflector plate is reapplied to the nozzle plate and the missile removed by hook'32.

Referring now to 1 1G. 1, all of the parts which are identical to those of the prior art have been identified by the same reference characters. Deflector plate 24 is not employed, however, and nozzle plate 12, abutments 26, 3t and finger 34 have been modified, these being identified,

respectively, by reference characters 12A, 26A, 30A and 34A. Other parts have been added, as will subsequently appear.

Nozzle plate 12A is provided with a central aperture 40 which is closed by a plug 42 (FIG. 2) having an O- ring seal 44 which seats against a circular surface 46. A cup-shaped rupture diaphragm 48 is disposed between the inner surface of the plug and the interior of the motor to prevent entry of moisture or foreign matter. This may be cemented or otherwise secured to the nozzle plate. Nozzles 22 are likewise provided with conventional blowout plugs or diaphragms (not shown) which serve a like purpose. A spider 50 is disposed within aperture 40 and serves as a support for one end of rod 20. When the plug is inserted in, aperture 40, nozzle plate 12 is functionally the same as in the prior art and all gas must exhaust through nozzles 22. When it is removed, however, the cross sectional area between the legs of the spider is added to the nozzle throat areas. It iswell known that the burning time of a solid rocket grain of progressive burning powder is a function of motor pressure and that motor pressure is a function of ratio of grain burning area to nozzle throat area. Thus, if the nozzle throat area is supplemented with additional exhaust area the motor pressure is reduced and the burning time is increased. The additional area in the example illustrated is such that the burning time is increased from about 4 seconds to about minutes. As willbe apparent, with the burning time so increased, motor pressure is so low that the grain burns-slowly and produces very short pulses with low thrust and may stop burning due to low internal motor pressure. 7

As previously set forth, deflector plate 24 of the prior art serves two functions, one of which is thrust neutralization and the other is provision of suitable abutments for the ramming of the missle onto its launcher rail or removal of same from the rail. Since it is not desired to modify the launcher loading or unloading apparatus in any way it is apparent that some structure must be provided in lieu ofthe deflector plate. For this purpose a ramming plate '52 is provided which is secured to the nozzle plate by a pair of screws 54. The opposite faces of this plate form abutments A, A which serve the same purpose as abutments 26, 30 of the prior art. As best shown in FIG. 3, this plate tapers along its length and is provided with anintermediate square portion 56 (FIG. 4), terminating in a bent finger 58 (FIG. 1), the

finger being of smaller cross sectional area than the square if an attempt be made to apply the diaphragm to the launcher. A non-removable screw 63 is carried by the piercing finger which may engage a threaded aperture 64 at the center of the plug.

In the operation of the apparatus, it will be assumed that the missile motor has been assembled at some point of its transportation to the launcher with plate '52 secured to the nozzle plate and extending through finger 34A, maintaining it projecting rearwardly of the nozzle. After assembly it is placed in a suitable protective container and the container and missle transported to the launcher. It will be assumed, also, that plug 42 is disposed at the launcher and is unavailable at any other site. The missile is then removed from the container and rammed onto the launching rail in conventional manner, plate 52 serving asthe necessary abutment for the ramming apparatus. After being rammed onto the launching rail and secured to same it is apparent that if an attempt be made to apply diaphragm 36 it will be pierced by finger 34A. It is also apparent that plug 42 cannot be applied to the nozzle plate.

since bent finger 58 occupies the space required for the plug. It is thus obvious to loading personnel that ramming plate 52 must be removed. Screws 54 are therefore removed and the plate is moved radially outwardly until the smaller section of the finger may be rotated within the square aperture in finger 34A, after which it may be bodily removed from the nozzle plate. Plug 42 is next applied to the threaded aperture in the nozzle plate until its 0-ring is in engagement with circular surface 46. When properly seated, finger 34A may be folded into engagement with the rear face of the plug and held in such position against the urge of spring 62, by screw 6?). Diaphragm 36 may now be applied to the launcher without being pierced by the finger. To ensure that plug 42 is fully seated with its O-ring in sealing engagement with circular surface 45, the pivotal axis of finger 34A is .so chosen relative to the rear surface of'the plug that the finger cannot fold against the plug, and screw.63 be engaged with threads intheplug, unless the plug seal is fully seated. The missile is now ready for launching from the launcher. i

It will now be assumed that it is desired to remove the unfired missile from the launcher. After diaphragm 36 is removed it is apparent that the missilecannot be removed from the launcher since there is no abutment for hook 32. Plate 52 must therefore be reapplied. It cannot be reapplied, however, unless plug 42 is removed since the bent finger must occupy the same space occupied by theplug. 7 that the plug must be removed. After removal of the plug, plate 52 may be reapplied to the nozzle plate and the missile removed by hook 32.

Obviously many modifications and variations ofthe present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. Safety apparatus for use with a missile propelled by a rocket motor and adapted to be launched from a launcher, said rocket motor having a predetermined exhaust nozzle area at its rear end to normally produce predetermined thrust for a predetermined time of burning of the motor propellant, comprising, in combination:

(a) an aperture in the rear end of the motor providing additional exhaust area sufficient to materially increase the burning time of the propellant and render the motor substantially non-propulsive, said aperture being accessible from the rear end of the launcher when the missile is loaded in same,

(b) removable closure means for closing said aperture, adaptedto be manually applied to the aperture after the missile has been loaded into the launcher and, when so applied, positively closing said aperture against passage of gas therethrough irrespective of the It is obvious to loading personnel, therefore pressure Within the motor, said closure means being so constructed to lock itself in the aperture as it is being manually applied thereto, and

() means adapted to be secured to the missile only when said closure means is removed from the aperture having an abutment thereon for permitting loading of the missile into the launcher.

2. Apparatus in accordance with claim 1, including;

(d) visual means associated with the launcher for indicating non-application of the closure means to the aperture, thereby indicating that the missile has not been readied for launching with said predetermined thrust.

3. Apparatus in accordance with claim 2 wherein said visual means comprises;

(e) a puncturable diaphragm for closing the launcher at a position rearwardly of the rocket motor,

(f) and a probe carried by the rocket motor for puncturing the diaphragm if the diaphragm is applied to the launcher without applying the closure means to the aperture.

4. Apparatus in accordance with claim 1 wherein said means for permitting loading of the missile into the launcher, comprises;

(g) a member detachably secured to the motor,

adapted to be engaged by the launcher loading mechanism, said member having means associated therewith for preventing application of said closure means to the aperture until after said member is removed from the motor.

5. Apparatus in accordance with claim 4 wherein said member is operatively associated with the launcher unloading mechanism and cannot be reapplied to the motor until after said closure means has been removed from the aperture.

6. Safety apparatus for use with a missile propelled by a rocket motor and adapted to be launched from a launcher, said rocket motor having a nozzle plate at its rear end and an annular row of angularly spaced nozzles extending therethrough providing predetermined exhaust nozzle area to normally produce predetermined thrust for a predetermined time of burning of the motor propellant, comprising, in combination:

(a) a central aperture extending through said nozzle plate providing additional exhaust area suflicient to materially increase the burning time of the propellant, said aperture having internal threads,

(b) a removable externally threaded plug engageable With said internal threads for closing said aperture,

(0) an abutment member removably secured to said nozzle plate in rearwardly spaced relation thereto, adapted to be engaged by the launcher loading and unloading mechanism,

(d) said abutment member, when secured to the nozzle plate, having a portion extending into said aperture for preventing application of the plug to the central aperture, thereby permitting loading and unloading of the missile into or from the launcher only when said plug is not applied to said aperture.

7. Apparatus in accordance with claim 6, including;

(e) a probe pivotally secured to said nozzle plate and through which a portion of said abutment member extends to maintain said prong extending rigidly in a rearward direction from said nozzle plate, in which position said prong will puncture a diaphragm for closing the launcher at a position rearwardly of the rocket motor, in event the diaphragm is applied to the launcher without removing the abutment member and pivoting the probe .to a non-puncturing position.

8. Apparatus in accordance with claim 7 including;

(7) a spring for maintaining said probe in its rearward direction after said abutment member has been removed from the nozzle plate.

9. Apparatus in accordance with claim 8 including;

(g) a threaded aperture in said plug,

(it) and a screw carried by said probe engageable with the threaded aperture only when said plug has been fully applied to said central aperture and in fully sealing engagement therewith, the probe thence being pivotable into engagement with the plug to its nonpiercing position and also locking the plug against rotation in said internal threads,

References Cited by the Examiner UNITED STATES PATENTS 2,515,049 7/50 Lauritsen et al. 35.6 2,693,757 11/54 Brandt 102-49 2,775,201 12/56 Conway 102-49 BENJAMIN A. BORCHELT, Primary Examiner.

SAMUEL W. ENGLE, Examiner. 

1. SAFETY APPARATUS FOR USE WITH A MISSILE PROPELLED BY A ROCKET MOTOR AND ADAPTED TO BE LAUNCHED FROM A LAUNCHER, SAID ROCKET MOTOR HAVING A PREDETERMINED EXHAUST NOZZLE AREA AT ITS REAR END TO NORMALLY PRODUCE PREDETERMINED THRUST FOR A PREDETERMINED TIME OF BURNING OF THE MOTOR PROPELLANT, COMPRISING, IN COMBINATION: (A) AN APERTURE IN THE REAR END OF THE MOTOR PROVIDING ADDITIONAL EXHAUST AREA SUFFICIENT TO MATERIALLY INCREASE THE BURNING TIME OF THE PROPELLANT AND RENDER THE MOTOR SUBSTANTIALLY NON-PROPULSIVE, SAID APERTURE BEIBG ACCESSIBLE FROM THE REAR END OF THE LAUNCHER WHEN THE MISSILE IS LOADED IN SAME, (B) REMOVABLE CLOSURE MEANS FOR CLOSING SAID APERTURE, ADAPTED TO BE MANUALLY APPLIED TO THE APERTURE AFTER THE MISSILE HAS BEEN LOADED INTO THE LAUNCHER AND, WHEN SO APPLIED, POSITIVELY CLOSING SAID APERTURE AGAINST PASSAGE OF GAS THERETHROUGH IRRESPECTIVE OF THE PRESSURE WITHIN THE MOTOR, SAID CLOSURE MEANS BEING SO CONSTRUCTED TO LOCK ITSELF IN THE APERTURE AS IT IS BEING MANUALLY APPLIED TO THERETO, AND (C) MEANS ADAPTED TO BE SECURED TO THE MISSILE ONLY 